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Checking shim clearance with feeler gauge

Posted: Mon Dec 10, 2007 3:56 pm
by -Nemesis-
A quick question for the mechanics:

I'm doing the shims on my 1uzfe on the passenger side bank as one is very noisy. I'm measuring clearance with a feeler gauge. The question is:

How hard do i force the feeler gauges in between the lobe and shim to check clearance?

You can't attack the shim from directly side on with a feeler gauage, you have to come down at a bit of an angle because of limited room. I noticed that I could get the feeler gauge in where it fits snug. But if I add up to another .1mm on some of them, if I press the feeler guage in hardish, it will still all of a sudden slide in between the lobe and the shim, once flat i can move it back and forth. What i'm wondering is if by pressing fairly hard on the guage, will it actually be slightly depressing the shim/bucket and give a false reading? Should I just get the feeler guage snug between the surfaces, or get it so I can only just force it in?

Any tips? (I've already got the suspect ones out and measured, i'm just paranoid now about whether I under-measured the tolerances....

Posted: Mon Dec 10, 2007 4:41 pm
by -Nemesis-
For example:

On the main suspect shim I found that I could get the feeler gauges in the gap set at .35mm with only moderate force. Once the feeler guage was in the gap they move around quite freely.

However on the same shim I found that even up to .49mm worth of guage I could still get it to slide between the shim and lobe using considerable force to get it in there initially. Once it was in there I could move it back and forth but feel it was getting a decent amount of pressure (drag) from the shim and lobe surfaces.

Posted: Mon Dec 10, 2007 6:11 pm
by L,C 60
The feeler guage should slide in the gap snug but not have to be forced.
If you have to force it in then the gap is to small for that particular size.

Posted: Mon Dec 10, 2007 6:19 pm
by -Nemesis-
Yeah that's what I was thinking. I guess the only issue is the angle that it requires to enter the gap initially because the feeler aproaches the shim surface at a downwards angle, but at such a small thickness it probably won't make a difference as the feelers bend.

At least they're easy to get to, nothing wrong with trial and error. One of the rears has been ticking its head off annoying me for years, ever so slowly getting louder. If the tick goes, i'm happy :D

Posted: Mon Dec 10, 2007 6:37 pm
by RUFF
You can get feeler guages with a bend in the tip to make it much easier with limited space.